S

een from a different viewpoint, the 1998 economic recession may have been a blessing in disguise. The fact that many workers got the axe saw people starting their own businesses in order to earn a living. Today, small and medium enterprises (SMEs) are one of the business groups that play a vital role in the national economy, especially in times of crisis.

Supported by natural resources, in this case raw materials and plenty of workers, Subang regency has good potential to develop SMEs.

Tofu is a processed food consumed by many people. According to data from the Trade Ministry, there are 160 SMEs in Subang, while Sumedang, known as a tofu industrial center, has 500 SMEs.

Observing this situation, some researchers from the Unit Development Center for Appropriate Technology in Subang at the Indonesian Institute of Sciences are working on project research titled 'The application of appropriate technology-based clean production in the small industry centers of tofu in Subang' which was funded by the Research and Technology Ministry in 2012.

The team consisted of a variety of disciplines: post-harvest technology, chemistry, socioeconomic agriculture and mechanical engineering. The fundamental principle was the concept of cleaner production, which aimed to improve efficiency in various areas.

The team was divided into three groups: a food team (from the post-harvest and chemical disciplines) did material efficiency and process engineering; an environment team processed liquid and solid waste treatment of tofu industries for fuel gas (biogas) to be reused for household needs; and an Energy team created the design and construction of the effective and efficient furnace of tofu in the process of soy porridge cooking, by utilizing heat energy that was normally discarded as a source of energy for reuse.

After conducting a survey on SMEs, Andi Taufan on the energy team gave a brief presentation about water management with plumbing techniques. One solution that could be applied to conserve water and energy (electrical energy pumps) was by using a roof tank. The basic idea was simple: how to relocate water when it was needed during the peak demand so that the electrical energy used to run the pump for at least eight hours a day could be reduced. This was energy and money efficiency.

 The water is supplied directly from the well using a pump that works for eight hours per day. In one day, the cooking process of 24 batches of tofu with a 0.21 m3/batch of water means that the total water need of the day is 4.98 cubic meters. The total electrical energy used to drive the pump reaches 0.81 kWh. One of the applications of cleaner production for the tofu industry focuses on energy efficiency. Therefore, the design of water supply systems is conducted by using the roof tank system.

The roof tank is designed with the plumbing system approach that refers to the Indonesian National Standard (SNI) in some phases: field surveys, problem identification, the calculation of water need and installation design. Calculations show the capacity of the roof tank to meet the water need in the manufacturing process of tofu and the needs of workers, which is 630 liters per day.

By using the appropriate tank with effective capacity, the pumps will work as much as eight times to meet the needs of water per day, with 0.25 kWh electric power needs. Then, the tank capacity is adjusted to 1000 liters, so the electrical power requirement is 0.16 kWh per day in which the pump works as much as five times.


Swistien Kustantyana
Citizen journalist
Jakarta